Explanation:
Thirty years ago NASA's exploration of Mars began. In
July of 1965 the
Mariner 4 spacecraft
flew within 6,000 miles of Mars and returned 21 pictures
of the mysterious red planet. NASA's continued
exploration of Mars has produced detailed views
of the red tinged Martian surface
like the one shown above which is a composite of 102 images
from the
Viking missions to Mars .
The composite was constructed by the
US Geological Survey.